CAJ | 학술논문

对MODIS卫星遥感亮温与气温、地温进行了不同时间尺度的大量的计算比对和相关性分析,以期得到直接采用实时MODIS亮温相对变化,结合地面实测地温来研究地震活动热异常的短临变化信息的具有统计意义的依据.结果表明:1)亮温与气温、地温从较长周期的时间尺度(月均值)上看,其相关性很好.而短周期(日均值)尽管明显低于较长周期,但仍然有着较好的相关性.2)通过大量计算比对发现,亮温均值与地温和气温的相关性随着像元面积的增大而逐渐升高.这表明,大气和环境的影响对单一像元而言较为明显.而这种影响可以由一定区域像元的亮温均值得到一些削弱,即一定区域的亮温均值与地温(Ocm)的相关性优于单个探测像元的亮温.基于此,在研究亮温相对变化时,应尽量避免采用单一像元的亮温值.利用一定区域的像元均值可能会达到一些排除干扰的效果;3)鉴于热红外亮温数据与地表实际测到的地表温度(Ocm)有着显著的相关性,将实时探测到的大面积均匀分布的亮温相对变化与地表实际测到的地表温度结合起来进行热异常变化信息研究,可望提升其可信度和有效性.
대MODIS위성요감량온여기온、지온진행료불동시간척도적대량적계산비대화상관성분석,이기득도직접채용실시MODIS량온상대변화,결합지면실측지온래연구지진활동열이상적단림변화신식적구유통계의의적의거.결과표명:1)량온여기온、지온종교장주기적시간척도(월균치)상간,기상관성흔호.이단주기(일균치)진관명현저우교장주기,단잉연유착교호적상관성.2)통과대량계산비대발현,량온균치여지온화기온적상관성수착상원면적적증대이축점승고.저표명,대기화배경적영향대단일상원이언교위명현.이저충영향가이유일정구역상원적량온균치득도일사삭약,즉일정구역적량온균치여지온(Ocm)적상관성우우단개탐측상원적량온.기우차,재연구량온상대변화시,응진량피면채용단일상원적량온치.이용일정구역적상원균치가능회체도일사배제간우적효과;3)감우열홍외량온수거여지표실제측도적지표온도(Ocm)유착현저적상관성,장실시탐측도적대면적균균분포적량온상대변화여지표실제측도적지표온도결합기래진행열이상변화신식연구,가망제승기가신도화유효성.
Through numerous comparison experiments and the correlation analysis at different time scales,the present study tried to get the important basis of statistic significance in aspect of the use of real-time relative changes of MODIS BT combined with field ST measurements from thermal infrared anomalies for directly investigating the short and imminent earthquake-related phenomena. Results of correlation analysis show that: 1 ) Significant correlation exists between brightness temperature, air temperature and ground temperature in the view of the longer cycle time scale ( monthly mean) , even in the case of short cycle ( daily means) , where the correlation is significantly lower than that of longer cycle, they still have good correlations; 2)The correlation between the mean brightness temperature and the surface temperature increases gradually with the increased pixel size involved. This indicates that the atmospheric and environmental effect on brightness temperature is more obvious for single pixel. This effect can be reduced by using mean brightness temperature of pixels in a certain region. In other words,the correlation between mean brightness temperature of pixels in a region and the surface temperature (0cm) is better than that of a single pixel. Consequently,when studying the relative changes in brightness temperature, it is suggested that we should try to avoid using the brightness temperature values of a single pixel; 3 ) The combination of the MODIS brightness temperature at large coverage with surface temperature in field might improve the feasibility and reliability of detection of the thermal IR anomalous change; it has been demonstrated by the significant correlation between the retrieved MODIS BT products and field ST measurements(0cm). In general,this study implies the statistical significance of investigating short and extemporaneous activities of earthquake phenomenon by means of analyzing temporal changes of the retrieved near real-time MODIS brightness temperature products coupled with the measurements of surface temperatures. It should be noted that the specific geographic environments which depend on the changing weather process and the complex geological setting could hamper the extraction of information of the short-term and impending abnormal seismic thermal changes. Therefore,we need to take fully into account the above-mentioned impacts when applying satellite thermal infrared data to earthquake prediction research and designing data processing methods.